I don’t know if I can provide enough information for this report to actually be useful, but I don’t have much available.
I passed by this Abyss of Yog multiple times per day as it was in an area where I stored loot. I guarantee that it has never not had me near it for more than 24 hours from the moment it was constructed.
When the event log first started saying it was abandoned, I was very confused and checked it with a repair hammer. It said 168 hours, so I just stopped paying attention to the event log reports.
I do have Statues of Refreshment randomly decaying for no reason all the time, but this is the first time I’ve had an altar behave this way, so I am left entirely clueless as to what happened here.
Happened to me as well, the altar was in the middle of my base on foundations and everything. But since the altar killed my thrall once, i wanted to demolish it. Took the decay as a sign
Just out of curiosity, was it placed on the same type of foundations or mixed?